Overall I really like this set. Most of the points below are quibbles.
Image 1) This pose is hit and miss for me. I like her head position (turned just away from the camera and tilted), and I like how her left (near) shoulder is rolled forward. Not everyone likes the hunched shoulder look, but for me it creates some interesting definition and contours around her back and neck. I do not like the position of the right arm, however. Particularly with this crop, in which you can't see the shoulder, elbow, or hand, that arm just looks like two random things sticking out from behind her head. Doing the old "hold my hand out to crop" to get rid of that right arm, I feel the image becomes a stronger headshot. That right hand also seems to be creating the poof of hair at 12 o'clock, which seems too unruly compared with the generally smoothly styled hairdo. (Speaking of hair, is that her real hair color or did you tint it in post? Love the color! And I like how the pale pink lipstick complements it.)
I go back and forth on whether I mind the bit of clothing you can see in the shot. On one hand, it's dark and unassuming, so it doesn't really draw the eye. On the other, had she pulled it down just a touch and/or you cropped up just a bit she would have appeared topless and you would have had a more standard beauty shot. In general, clothing is part of the narrative in a picture; if it's going to be such a minimal portion of the shot and so nondescript, it just as well might not be there. While on styling, I do like the choice of earring, just a little detail peaking out of the hair.
The lighting seems just a bit hot. At least on this monitor I'm seeing a hot spot on her near shoulder which unfortunately is large enough to start drawing my eye from her face.
Image 2) I really like the composition here. I also love the styling. That is a great shade of red to stand out from the neutrals used in the rest of the shot, and I like how the tones of the background, wig, and skin work together. (The hair is starting to get lost in the background in the upper right corner - again, at least on this monitor - but that doesn't bother me with the red to anchor the view.) And I like how the pattern in her top (jacket?) give texture to a decent portion of the frame without being distracting. The only nitpick I have is that the cage opening is not centered, partly because the engineer in me wants it more symmetric, but mostly because, while we have a nice view of her right eye, we can't see much of her left eye.
Image 3) I too like the expression. It's getting a bit close to duck-face, but with the tilt to her head and the smirk in her eyes the pout works. I also like the fairly close crop here. I'm not a fan of the hands in the hair. The hands add nothing for me - her fingers get lost in her hair, and her hands and forearms blend into the background a bit. If anything, the hands and forearms block what might have been nice detail in the hair styling. I also might have considered a bit more tint to the background, to help her stand out from it a bit (particularly her torso).
Again, these are generally nitpicking, I really like the feel of this set. Well done!
In the 3rd one, my eyes are distracted by the contrast with the hair (dark) and the lights, but this image itself is great (model, pose, facial expression).
Perhaps high key it (processing wise), the hair to be more balanced with the perfect tones on the face, arms and clothing. Just a suggestion, but great either way.